Dentist&#39;s water heater



Nov. 10l 1925. Y

V C. E. PARKHURST DNTISTS WATER HEATER Filed May 20. 1922 Patented Nov. 1Y0, 1925.

CHARLES E. PAE'KHURST, OE soME'EvIL'LE, MASSACHUSETTS.-

DENTIsTs WATERy HEATER.

Application filed May 20, 1922. Serial No.` 562,491.

To all whom t may concern.'

Beit known that I, CHARLES E. PARK- IIURsT, a citizen of the United States of America, and resident of Somerville, in the county of Middlesex and State-of Massachu- Setts,"have invented new and useful Improvements' in Dentists W'ater Heaters, of which the 'following is a specification.

This invention relates to water heaters and consists of a water heater especially adapted to be employed for supplying waterv for oral use by dental patients.A y

It is found in practice that water heaters using 'gaseous or liquid fuel give off when in operation a disagreeable odor regardless of whether the water is being raised to a high 'or low temperature. By reason of the fact that water for oral use in dental surgery is to be'rai'sed only' to a moderate temperature it is desirable that the heater b'e'conveniently located so that the dentist himself can' control its operation.- The odor, however, produced by suchpdevice's becomes so unpleasant and offensive in the sr'n'a-ll rooms ordinarily usedby dentists as to practically preclude their use. f

Objectsof the invention are to heat water to a moderate temperature rather than to high temperature as in usualtypeof water heaters, to obviate the disagreeable odor produced' by such devices, to provide means for accurately -cont-rolling the temperature of the heated-water, and in general to improve devices 'of this kind and render' thennl satiefactory and eiiicient in service. y

The invention comprises a. water heater having a casing, a water coil and a fuel bnrnerf-in the casing-,and means producing complete'combustion of the fuel without directfcontacjt 'of the flame with the heating coi-lf. fWhile the meansmay comprise apparatus for 'directingthe name downwardly, orfa'lgaplor yspace' in thel water coil, or an enlargement of the casing, .it preferably comprises combination of all three.y 1 The invention further comprises ineans'ifor preventing water 'of condensation from interfering'with the operation of the burner and producing `incmnplete combustion" of the fuel.

For the 'purpose 'of illustrating the invention one `concreteiembodiment thereof is Shown in the Aacco"mpanying drawings, in which ,t

' Fig. 1 is a'front elevational View;

Fig. 2 is a verticalV Section through the heater; i

Fig. 3 is a plan view with the top of the casing removed;

Fig. et is an' eleafationalv view of the burner;

Fig. 5 is a. sectionon the line 5-5 of F 4.

The enibodiment'of the invention shown for the purposey of illustration comprises a dentists water heater adapted toI be attached to the standard upon which Vthe dentist-s cuspido'r is mounted and toy be supplied with water from the supply pipe to the'latter. The preferred form of heater is shown in the accompanying drawings in whichA indicates the casing, B the water supply pipe and C the fluid fuel pipe. The supply of water iS controlled by a valve 4, the supply of fuel, preferably gas, by a valve 5 and both valves are preferably'simultaneously operated'by a valve spindle 6 actuated by handle 7. Within casing A is a burner 8 connected to the fluid supply valve. 5 by a transverse pipe/'.9 in the base of the casinghaving an opening 10 through which'v the gas enters the burner, pipe 9 being in turn connected to a pipe 11 which leads directly toy valve '5..` A pilot burner 12 is likewise supplied from a smaller pipe 13 which connects 'directly with the fuel Supply pipe 6.

The water supply pipe 14 leading vfrom valve 4l enters the base of the casing through an opening 15 and is attached to a water tube of suitable material, such as "copper, which forms the water.-coil-within` the `casing. The lower portion-of the coil is arranged in circulaire convolutions 16 about the base of burner 8 and adjacent the casing A and thence leads upwardly by a substantially vertical section 17 to a point adjacent the topof burner 8 and is there formed ina coil 18 arranged to substantially' ill the upper portion of the casing as clearly indicated in Figs?) which shows the upper portion of the 'ca-singin plan.

Asv Shown'the tubing is arranged in iconvolutions, each convolution having a number of loops 19, these loops beingg staggered in adjacent coiivoluti'onsy So that in plan view the upper water coil provides 'al central or axial opening` 2O directly above thev burner 8 and a' plurality of openings .21, in the form shown Iseven in number, parallel to the central opening through vwhich the heated from said coils, and a burner arranged in said casing to direct the flame downwardly into the space provided by said enlargement between the coils and not into direct initial contact therewith.

3. A dentist-s water-heater comprising a casing having air openings at its upper and lower ends and a central enlargement, a water coil in said casing spirally disposed below said enlargement, a second water coil substantially filling the space above said enlargement but having longitudinal openings therethrough, means spacing said coils from said casing to provide air passages therebetween, a burner axially disposed in said casing and arranged to direct a single 4circle of flame downwardly and fanwise into the space provided by said enlargement, said burner cooperating with the enlargement and the disposition of the coils to prevent the flame from initially reaching the coils thereby to prevent disagreeable odors.

4. A water-heater comprising casing having air openings at its upper and lower ends and a central enlargement, a water coil disposed in said casing below said enlargement, a second water coil substantially filling the space above said enlargement but providing longitudinal openings therethrough, a burner arranged in said casing intermediate the coils to direct the flame downwardly into the space provided by said enlargement between the coils and not into direct contact therewith, and a cap upon the top of said burner overhanging the sides thereof to prevent water of condensation from the overlying coil from reaching the burner openings and interfering with the combustion of the fuel.

5. A water-heater comprising a casing having air openings at its upper and lower ends and a central enlargement, a water tube coiled in the upper and'lower portions of said casing, a burner axially disposed in said casing terminating adjacent said enlargement. and arranged to direct the ame downwardly and outwardly in the region of said enlargement` and a member extending over and beyond the sides of the'burner to prevent water of condensation on the upper coil from dripping thereon.

Signed by me at Boston, Mass., this 16th day of May, 1922.

CHARLES E. PARKHURST 

